Patients confined to wheelchairs face the prospect of developing decubitus ulcers or “bed sores” on their buttocks. These ulcers form at bony locations when prolonged sitting pressure reduces blood circulation below the level required to sustain tissue life. Skin breakdown can also occur when the patient is seated on a wheelchair cushion that does not provide adequate ventilation and causes the skin to remain excessively moist and warm for protracted periods. A healthy subject seated for a prolonged period in a single position will sense discomfort and eventually pain from the reduced blood circulation, and will change positions. However, if the patient is paralyzed, disoriented, sick or otherwise disabled, they may be unaware of the discomfort or pain, or may be unable to change position.
Various wheelchair cushions are commercially available for reducing the risk of developing “bed sores” by spreading the person's weight over as much area as possible. Such cushions include inflatable cushions, fluid-filled cushions, gel filled cushions, foam cushions and combinations thereof. As a general matter, gel-filled and foam cushions provide a soft surface but do little to reduce pressure exerted upon the bony regions of the buttock and contribute to moisture and heat build up. Fluid filled cushions (e.g., cushions filled with water) help reduce the pressure exerted upon the bony regions of the buttock, but are heavy and subject to leaking of the fluid. Inflatable cushions (e.g., cushions filled with pressurized air) are lightweight and help reduce the pressure exerted upon the bony regions of the buttock. However, inflatable cushions are also subject to leaking, with a resultant loss in effectiveness and eventual “bottoming out” of the person seated on the cushion (i.e., direct contact between the person and the seat of the chair). Failure to reinflate the cushion to the proper pressure for an extended period of time can eventually lead to the development of “bed sores”.
Cushion inflation monitoring systems are known, such as the system described in U.S. Pat. No. 5,487,197. However, such inflation monitoring systems are customized for use with a particular type and style of cushion. Persons confined to wheelchairs spend a significant portion of the day seated in the wheelchair, and are understandably sensitive to selecting just the right cushion.
Hence, a need exists for an inflation monitoring system which can monitor the inflation pressure in a wide variety of inflatable cushions so as to provide persons with the benefit of an inflation pressure monitor in connection with a wider range of cushion types and styles.